An 81-year-old woman presented with a 2-week history of increasing redness, swelling, blistering, and pain in the left lower leg. She had been diagnosed as having bullous erysipelas and treated with oral cefuroxime, without improvement. On close questioning, the patient reported that she had experienced 4 similar episodes of painful erythema and edema in the same area over the past 20 years. Each of these episodes was preceded by an acute urinary tract infection and slowly resolved with antibiotic therapy. Before the current eruption, she had again noticed severe burning on urination that had rapidly improved with oral co-trimoxazole therapy.